Ultrasonographic findings in Cairn Terriers with preclinical renal dysplasia

Abstract

Renal dysplasia is a hereditary disease characterized by abnormal differentiation of renal tissue. The ultrasonographic appearance of dysplastic canine kidneys has been reported in the late stage of the disease where inflammatory and degenerative changes are already present and the dogs are in chronic renal failure. In this study, we describe the ultrasonographic appearance of the kidneys of five related Cairn Terriers affected with renal dysplasia before the onset of clinical or laboratory evidence of renal failure. Common findings included poor corticomedullary definition and multifocal hyperechoic speckles in the renal medulla, or a diffusely hyperechoic medulla. Severity of ultrasonographic changes was related to the severity of histopathologic findings. The ability to detect dysplastic changes before clinical signs develop makes ultrasound a potentially useful screening method for canine renal dysplasia.

Fig. 1

(A–C): Dorsal plane ultrasound images of the left kidney of three dogs at the age of 4 months with different degrees of ultrasonographic changes. (A) Dog 1 with mild hyperechoic speckling of the medulla and slightly reduced corticomedullary definition. (B) Dog 4 had moderate ultrasonographic changes. The predominant abnormality is the hyperechoic speckling of the medulla. (C) Dog 3 with severe ultrasonographic changes: there is poor corticomedullary definition and a hyperechoic medulla. Renal length measured between 3.3 cm (Dog 3) and 3.8 (Dog 1).

Fig. 2

Dorsal plane ultrasound images of the left kidney of Dog 4 at the age of 4 months (A) and 16 months (B): The ultrasonographic changes were more severe at 16 months with persistent hyperechoic medullary speckles but a decreased corticomedullary definition. Mild pyelectasia is also present.

Fig. 3

Dorsal plane ultrasound images of the left kidney of Dog 2 at the age of 4 months (A), 9 months (B), and 24 months (C). The ultrasonographic changes include poor corticomedullary definition and medullary hyperechogenicity, the changes were severe at all time points.

Fig. 4

H&E staining of the renal biopsy sample of Dog 4, ×40 magnification. Two glomeruli are included, a large, normally developed glomerulus, and a small fetal glomerulus with a dilated Bowman’s capsule (arrow).